Broadly tunable graphene plasmons using an ion-gel top gate with low control voltage
Broadly tunable graphene plasmons using an ion-gel top gate with low control voltage
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使用具有低控制电压的离子凝胶顶栅的广泛可调石墨烯等离子体激元
DOI：
10.1039/c5nr05175d
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发表时间：
2015-01-01
期刊：
影响因子：
6.7
通讯作者：
Dai, Qing
中科院分区：
文献类型：
--
作者：
Hu, Hai;Zhai, Feng;Dai, Qing
石墨烯的静电可调性在活性等离子体领域至关重要，并将有利于可调谐红外和太赫兹光学元件的应用。实现广泛可调性的关键是在石墨烯中实现高载流子密度。在这里，我们使用离子凝胶（目前具有超高电容的最有效的介电体之一）来实现低电压调制（类似于从Dirac点移出的4 V）的广泛可调谐石墨烯等离子体（类似于1270 cm(-1)）。我们进一步探讨了石墨烯等离子体激元与离子凝胶分子振动模式之间的耦合，因为强等离子体激元-声子耦合可以将等离子体激元共振峰分裂成多峰，并降低其可调性。我们的实验表明，在石墨烯/离子凝胶体系中，弱等离子体子-声子耦合对等离子体子性质的影响有限。这些特性使离子凝胶成为广泛可调谐石墨烯等离子体器件的有效介质，例如新型光学调制器、滤波器和波长复用器。
The electrostatic tunability of graphene is vital in the field of active plasmons and would be beneficial in tunable infrared and terahertz optical element applications. The key to realizing broad tunability is achieving high carrier densities in graphene. Here we use an ion-gel, currently one of the most efficient dielectrics with ultra-high capacitance, to realize broadly tunable graphene plasmons (similar to 1270 cm(-1)) with low voltage modulation (similar to 4 V shifted from the Dirac point). We further explore the coupling between graphene plasmons and the molecular vibration modes of the ion-gel, since strong plasmon-phonon coupling can split the plasmon resonance peak into multi-peaks and reduce their tunability. Our experiments demonstrate weak plasmon-phonon coupling in the graphene/ion-gel system, which has limited effects on plasmon properties. These properties make ion-gels an effective dielectric for broadly tunable graphene plasmonic devices, such as new optical modulators, filters and wavelength multiplexers.